1. CRFS Technical Meeting LC Operations Update November 8, 2011

2. Topics Operations Update Real-time Evaporation Project Lake Mead Bathymetry

3. 1,220 25.877 maf Lake Powell Lake Mead 3,700 24.322 maf Not to Scale 1,116.0 feet 12.98 maf in storage 50% of capacity Observed Unregulated Inflow into Powell = 16.77 maf (139% of average) 12.52 maf 1.16 maf 895 3,370 0.0 maf 2.0 maf 1.9 maf 0.0 maf Dead Storage 9.5 maf 16.36 maf 3,643 End of Water Year 2011 Conditions 3,575 3,653.0 feet 17.59 maf in storage 72% of capacity 1,14515.9 maf 1,075 9.4 maf

4. End of Water Year 2011 Lake Mead elevation end of WY 2011: 1116.04 feet Water Use in the Lower Basin has been lower than expected in CY 2011 –California and Nevada are currently projected to come in under their annual apportionments –Mexico deliveries are expected to be reduced this year under provisions of Minute 318 Over the past water year, Lake Mead’s surface water elevation has increased approximately 38.64 feet Despite wet conditions in the Upper Colorado River Basin, the Lower Colorado River Basin remained dry and hot

5. Lower Basin Side Inflows Glen Canyon to Hoover in WY/CY 2011 1,2 Month in WY/CY 2011 Intervening Flow Glen Canyon to Hoover (KAF) Intervening Flow Glen Canyon to Hoover (% of Average) Difference From 5-Year Average (KAF) HISTORYHISTORY October 201080136%+21 November 20101327%-35 December 2010248251%+149 January 20117497%-2 February 20118491%-8 March 20117796%-3 April 2011140233%+80 May 2011104212%+55 June 201172313%+49 July 201174148%+24 August 20119689%-13 September 201194134%+24 October 201165110%+6 PRJPRJ November 201148 December 201199 WY11 Totals1,156142%+341 CY11 Totals1,027126%+212 1 Values were computed with the LC’s gain-loss model for the most recent 24-month study. 2 Percent of average are based on the 5-year mean from 2006-2010 in CY 2011.

6. Water Year 2012 Projected Operations August 2011 Most Probable 24-Month Study projected Lake Mead elevation on Jan 1, 2011 to be 1134.12 feet –Currently projecting 1133.92 feet ICS Surplus Condition to govern Lake Mead operations Mexico deliveries may be reduced –Minute 318 signed to allow Mexico to store up to 260 KAF through 2013

8. August 2011 Results from CRSS Probabilities of occurrence, values in percent Event or System Condition 20122013201420152016 Upper Basin Equalization release from Powell 10057545245 Balancing release from Powell 00124 8.23 maf release from Powell 043453942 7.48 maf release from Powell 00079 7.00 maf release from Powell 00000 Lower Basin Shortage – any amount (Mead ≤ 1,075) 00017 Shortage – 1 st level (Mead ≤ 1,075 and ≥ 1,050)00017 Shortage – 2 nd level (Mead < 1,050 and ≥ 1,025)00000 Shortage – 3 rd level (Mead < 1,025 )00000 Surplus – (Domestic, Quantified, or Flood Control) 043474546 Surplus – Flood Control014710 Normal or ICS Surplus 10057535448

9. Lower Basin Surplus & Shortage through 2026

10. YAO Operations Update Brock and Senator Wash conservation year-to-date through November 3, 2011 –Brock105,500 AF –Senator Wash92,300 AF Excess Flows to Mexico year-to-date through November 6, 2011 62,982 AF 1 All values are provisional

11. Real Time Evaporation At Lake Mead 5-Year cooperative project with the USGS Measure and obtain hourly evaporation rates (and other parameters) from Lake Mead Develop new monthly coefficients for use in long-term modeling efforts Maintain program into the future

12. Comparison to Evaporation Rates in 24 Month Study *provisional Month24-Month StudyUSGS MeasuredDifference Mar 201033285 Apr 201041365 May 201047 0 Jun 201055496 Jul 201068662 Aug 20107073-3 Sep 20105961-2 Oct 20104255-13 Nov 20104255-13 Dec 201037307 Jan 2011312011 Feb 20112931-2 Mar 201133258 Apr 201140346 May 201147461 Jun 201157525 Jul 2011735419 Aug 2011806119 Sep 2011675413

13. Impacts Will reduce error associated with 24-Month Study side inflow to Lake Mead term Since February 2010, average difference is about 4 KAF, or a total of 73 KAF New monthly coefficients for use with Lake Mead Evaporation will be derived Lower Basin is actively working with CBRFC to forecast side inflows as well Would like to keep project going, and expand to Lake Mohave

14. Area-Capacity Update Developed with 2001 underwater bathymetric survey and 2009 LiDAR survey LCRO-GIS completed a thorough review and re-derived final surface area and capacity tables External review by Reclamation’s Provo office –Methodology determined to be sound Impacts Analysis –Comparison against 1963 data –Sensitivity analysis: 24-Month Study and CRSS Report Finalized –Available at: http://www.usbr.gov/lc/region/g4000/LM_AreaCapacityTables2009.pdf http://www.usbr.gov/lc/region/g4000/LM_AreaCapacityTables2009.pdf Implementation Date January 1, 2012

18. Lower Colorado River Operations For further information: http://www.usbr.gov/lc/region